Imagine you're at your favorite burger spot. You scan the menu for the best cheeses, toppings and buns but at the bottom of the menu, in small, italicized print you see this warning: “Consuming undercooked meats may increase risk of foodborne illness.”

Could comet clusters, or something other-worldly, explain this cosmic flicker?

January 10, 2017

With more than 100 billion stars in the Milky Way galaxy, there are plenty of celestial objects for scientists to survey. Every once in a while, astronomers see something puzzling, prompting explanations that may seem even more out there: planetary collisions, comet clusters or even aliens.